Hypermethylation of the DPYD promoter region is not a major predictor of severe toxicity in 5-fluorouracil based chemotherapy

<p>Abstract</p> <p>Background </p> <p>The activity of dihydropyrimidine dehydrogenase (DPD), the key enzyme of pyrimidine catabolism, is thought to be an important determinant for the occurrence of severe toxic reactions to 5-fluorouracil (5-FU), which is one of the most commonly prescribed chemotherapeutic agents for the treatment of solid cancers. Genetic variation in the DPD gene (DPYD) has been proposed as a main factor for variation in DPD activity in the population. However, only a small proportion of severe toxicities in 5-FU based chemotherapy can be explained with such rare deleterious DPYD mutations resulting in severe enzyme deficiencies. Recently, hypermethylation of the DPYD promoter region has been proposed as an alternative mechanism for DPD deficiency and thus as a major cause of severe 5-FU toxicity.</p> <p>Methods </p> <p>Here, the prognostic significance of this epigenetic marker with respect to severe 5-FU toxicity was assessed in 27 cancer patients receiving 5-FU based chemotherapy, including 17 patients experiencing severe toxic side effects following drug administration, none of which were carriers of a known deleterious DPYD mutation, and ten control patients. The methylation status of the DPYD promoter region in peripheral blood mononuclear cells was evaluated by analysing for each patient between 19 and 30 different clones of a PCR-amplified 209 base pair fragment of the bisulfite-modified DPYD promoter region. The fragments were sequenced to detect bisulfite-induced, methylation-dependent sequence differences.</p> <p>Results </p> <p>No evidence of DPYD promoter methylation was observed in any of the investigated patient samples, whereas in a control experiment, as little as 10% methylated genomic DNA could be detected.</p> <p>Conclusion </p> <p>Our results indicate that DYPD promoter hypermethylation is not of major importance as a prognostic factor for severe toxicity in 5-FU based chemotherapy.</p

Use of Diabetes Data Management Software Reports by Health Care Providers, Patients With Diabetes, and Caregivers Improves Accuracy and Efficiency of Data Analysis and Interpretation Compared With Traditional Logbook Data: First Results of the Accu-Chek C

We assessed users’ proficiency and efficiency in identifying and interpreting self-monitored blood glucose (SMBG), insulin, and carbohydrate intake data using data management software reports compared with standard logbooks. This prospective, self-controlled, randomized study enrolled insulin-treated patients with diabetes (PWDs) (continuous subcutaneous insulin infusion [CSII] and multiple daily insulin injection [MDI] therapy), patient caregivers [CGVs]) and health care providers (HCPs) who were naïve to diabetes data management computer software. Six paired clinical cases (3 CSII, 3 MDI) and associated multiple-choice questions/answers were reviewed by diabetes specialists and presented to participants via a web portal in both software report (SR) and traditional logbook (TL)  formats. Participant response time and accuracy were documented and assessed. Participants completed a preference questionnaire at study completion. All participants (54 PWDs, 24 CGVs, 33 HCPs) completed the cases. Participants achieved greater accuracy (assessed by percentage of accurate answers) using the SR versus TL formats: PWDs, 80.3 (13.2)% versus 63.7 (15.0)%, P &lt; .0001; CGVs, 84.6 (8.9)% versus 63.6 (14.4)%, P &lt;.0001; HCPs, 89.5 (8.0)% versus 66.4 (12.3)%, P &lt; .0001. Participants spent less time (minutes) with each case using the SR versus TL formats: PWDs, 8.6 (4.3) versus 19.9 (12.2), P &lt; .0001; CGVs, 7.0 (3.5) versus 15.5 (11.8), P = .0005; HCPs, 6.7 (2.9) versus 16.0 (12.0), P &lt; .0001. The majority of participants preferred using the software reports versus logbook data. Use of the Accu-Chek Connect Online software reports enabled  PWDs, CGVs, and HCPs, naïve to diabetes data management software, to identify and utilize key diabetes information with significantly greater  accuracy and efficiency compared with traditional logbook information. Use of SRs was preferred over logbooks.Keywords: diabetes software, insulin, self-management, self-monitoring of blood glucose, SMB

Clinical Implementation of DPYD Pharmacogenetic Testing to Prevent Early-Onset Fluoropyrimidine-Related Toxicity in Cancer Patients in Switzerland.

The implementation of pharmacogenetic testing into clinical practice has been a slow process so far. Here, we review the implementation of pre-treatment testing of dihydropyrimidine dehydrogenase gene (DPYD) risk variants to prevent early-onset fluoropyrimidine (FP)-related toxicity in cancer patients in Switzerland based on data of a large Swiss diagnostic center. In January 2017, the Swiss Federal Office of Public Health introduced the reimbursement of DPYD testing by the compulsory health insurance in Switzerland based on evidence for the clinical relevance of DPYD-risk variants and the cost-effectiveness of pre-treatment testing, and on the availability of international guidelines. However, we did not observe a strong increase in DPYD testing at our diagnostic center from 2017 to 2019. Only a low number of DPYD-testing requests (28-42 per year), concerning mostly retrospective investigations of suspected FP-toxicity, were received. In contrast, we observed a 14-fold increase in DPYD testing together with a strong shift from retrospective to pre-treatment test requests upon the release of recommendations for DPYD testing prior to FP-treatment in April 2020 by the European Medicines Agency. This increase was mainly driven by three geographic regions of Switzerland, where partner institutions of previous research collaborations regarding FP-related toxicity are located and who acted as early-adopting institutions of DPYD testing. Our data suggest the important role of early adopters as accelerators of clinical implementation of pharmacogenetic testing by introducing these policies to their working environment and educating health workers from their own and nearby institutions

Design of percutaneous transluminal coronary angioplasty balloon catheters.

BACKGROUND Eight commercially available percutaneous transluminal coronary angioplasty (PTCA), including semi-compliant and non-compliant balloons, have been assessed in detail on their tip, balloon, shaft, RX-Port, and hypotube design. Important performance characteristics such as tip deformation, balloon elongation, and deflation rate have been quantified. METHODS Five catheters of each model were evaluated during various tests. The robustness of the tips was evaluated through compression, measuring any occurrence of damage. The longitudinal growth of the balloons was recorded during inflation up to Rated Burst Pressure (RBP). The forces required to move the catheter forward and retract it into the guide catheter were measured in a simulated use test setup. The deflation behavior was studied by measuring extracted contrast media over time. Furthermore, balloon compliance and catheter dimensions were investigated. RESULTS The outer dimensions of the catheter were found to be smallest at the hypotube (0.59-0.69 mm) and highest at the balloon, respectively, the crossing profile (0.9-1.2 mm). The tip diameter increased after compression by 1.7-22%. Cross-sections of the folded balloons revealed a tri- and two-fold, respectively. The measured balloon elongation ranged from 0.6 to 2.0 mm. After the inflation of the balloon, an increase in friction between the guide wire and the catheter was observed on four catheters. A maximum increase of 0.12 N to 1.07 N was found. Cross-sections of the RX-Port revealed a semicircular-shaped inflation lumen and a circular guide wire lumen. The measured deflation rate ranged from 0.004 to 0.013 µL/s, resulting in an estimated balloon deflation time of 10.2-28.1 s. CONCLUSION This study provides valuable insights into the design characteristics of RX PTCA balloon catheters, which can contribute to facilitating the development of improved catheter designs and enhancing clinical outcomes. Distinctions between SC and NC catheters, such as balloon performance and dimensions, are evident. It is important to note that no single catheter excels in all aspects, as each possesses unique strengths. Therefore, it is essential to consider individual intervention requirements when selecting a catheter. The research also identifies specific catheter weaknesses, such as reduced wall thickness, fringes at the tip, and reduced performance characteristics

Reaching absent and refusing individuals during home-based HIV testing through self-testing-at what cost?

Introduction: In the HOSENG trial (NCT03598686), the secondary distribution of oral self-tests for persons absent or refusing to test during a home-based HIV testing campaign in rural Lesotho resulted in an increase in testing coverage of 21% compared to a testing campaign without secondary distribution. This study aims to determine the per patient costs of both HOSENG trial arms. Method: We conducted a micro-costing study to estimate the cost of home-based HIV testing with (HOSENG intervention arm) and without (HOSENG control arm) secondary self-test distribution from a provider's perspective. A mixture of top-down and bottom-up costing was used. We estimated both the financial and economic per patient costs of each possible testing cascade scenario. The costs were adjusted to 2018 US$. Results: The overall provider cost for delivering the home-based HIV testing with secondary distribution was US$36,481 among the 4,174 persons enumerated and 3,094 eligible for testing in the intervention villages compared to US$28,620 for 3,642 persons enumerated and 2,727 eligible for testing in the control. The cost per person eligible for testing was US$11.79 in the intervention vs. US$10.50 in the control. This difference was mainly driven by the cost of distributed oral self-tests. The cost per person tested was, however, lower in intervention villages (US$15.70 vs. US$22.15) due to the higher testing coverage achieved through self-test distribution. The cost per person confirmed new HIV+ was US$889.79 in the intervention and US$753.17 in the control. Conclusion: During home-based HIV testing in Lesotho, the secondary distribution of self-tests for persons absent or refusing to test during the visit reduced the costs per person tested and thus presents a promising add-on for such campaigns. Trial Registration:https://ClinicalTrials.gov/, identifier: NCT03598686

Investigation of Different Library Preparation and Tissue of Origin Deconvolution Methods for Urine and Plasma cfDNA Methylome Analysis.

Methylation sequencing is a promising approach to infer the tissue of origin of cell-free DNA (cfDNA). In this study, a single- and a double-stranded library preparation approach were evaluated with respect to their technical biases when applied on cfDNA from plasma and urine. Additionally, tissue of origin (TOO) proportions were evaluated using two deconvolution methods. Sequencing cfDNA from urine using the double-stranded method resulted in a substantial within-read methylation bias and a lower global methylation (56.0% vs. 75.8%, p ≤ 0.0001) compared to plasma cfDNA, both of which were not observed with the single-stranded approach. Individual CpG site-based TOO deconvolution resulted in a significantly increased proportion of undetermined TOO with the double-stranded method (urine: 32.3% vs. 1.9%; plasma: 5.9% vs. 0.04%; p ≤ 0.0001), but no major differences in proportions of individual cell types. In contrast, fragment-level deconvolution led to multiple cell types, with significantly different TOO proportions between the two methods. This study thus outlines potential limitations of double-stranded library preparation for methylation analysis of cfDNA especially for urinary cfDNA. While the double-stranded method allows jagged end analysis in addition to TOO analysis, it leads to significant methylation bias in urinary cfDNA, which single-stranded methods can overcome

Response to ranibizumab therapy in neovascular AMD - an evaluation of good and bad responders

Background: Treatment of neovascular age-related macular degeneration (AMD) with Lucentis® shows a broad spectrum regarding the course of visual acuity (VA). While some patients show a good response (increase in VA), others disclose much less promising results. Patients and Methods: A retrospective data analysis of all eyes treated for neovascular AMD at the University Hospital of Zurich, Switzerland for at least 12 months was carried out. The courses of VA between the 90th (good responders, GR) and the 10th (bad responders, BR) percentiles were compared at 3, 12 and 24 months from baseline. An analysis regarding demographic data, lesion type and size as well as injection frequency and visits was done and predictive factors for GR and BR were evaluated. Results: Marked differences in the course of VA between GR (n = 30) and BR (n = 30) are already observed 3 months from baseline. In GR the gains in VA after 3, 12 and 24 were 15.7 ± 9 letters ETDRS, 25.3 ± 7 and 14.0 ± 14. BR showed a deterioration of 8.3 ± 11 letters ETDRS after 3, 22.1 ± 8 after 12 and 23.6 ± 13 after 24 months. The gender distribution was equal with a higher percentage of female patients (64 % in BR and 66 % in GR). The baseline VA was statistically significantly lower in GR (45.7 ± 10 vs. 55.4 ± 11, p < 0.05) than in BR. No other significant differences in baseline data were found, and no predictor for group membership could be identified. Conclusions: Only the course of VA in the first three months seems to be of value for an estimation of the response to treatment. In the future the response to treatment in the early phase may influence the treatment algorithm and the injection frequency

Comparison of methods for donor-derived cell-free DNA quantification in plasma and urine from solid organ transplant recipients.

In allograft monitoring of solid organ transplant recipients, liquid biopsy has emerged as a novel approach using quantification of donor-derived cell-free DNA (dd-cfDNA) in plasma. Despite early clinical implementation and analytical validation of techniques, direct comparisons of dd-cfDNA quantification methods are lacking. Furthermore, data on dd-cfDNA in urine is scarce and high-throughput sequencing-based methods so far have not leveraged unique molecular identifiers (UMIs) for absolute dd-cfDNA quantification. Different dd-cfDNA quantification approaches were compared in urine and plasma of kidney and liver recipients: A) Droplet digital PCR (ddPCR) using allele-specific detection of seven common HLA-DRB1 alleles and the Y chromosome; B) high-throughput sequencing (HTS) using a custom QIAseq DNA panel targeting 121 common polymorphisms; and C) a commercial dd-cfDNA quantification method (AlloSeq® cfDNA, CareDx). Dd-cfDNA was quantified as %dd-cfDNA, and for ddPCR and HTS using UMIs additionally as donor copies. In addition, relative and absolute dd-cfDNA levels in urine and plasma were compared in clinically stable recipients. The HTS method presented here showed a strong correlation of the %dd-cfDNA with ddPCR (R 2 = 0.98) and AlloSeq® cfDNA (R 2 = 0.99) displaying only minimal to no proportional bias. Absolute dd-cfDNA copies also correlated strongly (τ = 0.78) between HTS with UMI and ddPCR albeit with substantial proportional bias (slope: 0.25; 95%-CI: 0.19-0.26). Among 30 stable kidney transplant recipients, the median %dd-cfDNA in urine was 39.5% (interquartile range, IQR: 21.8-58.5%) with 36.6 copies/μmol urinary creatinine (IQR: 18.4-109) and 0.19% (IQR: 0.01-0.43%) with 5.0 copies/ml (IQR: 1.8-12.9) in plasma without any correlation between body fluids. The median %dd-cfDNA in plasma from eight stable liver recipients was 2.2% (IQR: 0.72-4.1%) with 120 copies/ml (IQR: 85.0-138) while the median dd-cfDNA copies/ml was below 0.1 in urine. This first head-to-head comparison of methods for absolute and relative quantification of dd-cfDNA in urine and plasma supports a method-independent %dd-cfDNA cutoff and indicates the suitability of the presented HTS method for absolute dd-cfDNA quantification using UMIs. To evaluate the utility of dd-cfDNA in urine for allograft surveillance, absolute levels instead of relative amounts will most likely be required given the extensive variability of %dd-cfDNA in stable kidney recipients